Carburetor



Oct. 28,' 1930. s. EQ MELKMAN CARBURE'I'OR Filed July 7, 1927 Patented occ 28,".1930

vUNITED s'raxrasv PATENT oFFlcl-zi sAL'BimANUEL HELKMAN, or BRUSSELS, BELGIUM, AssIeNoR 'ro THELMA CARBU- RA'roR COMPANY, SOCIETE ANoNYME, or BRUSSELS, BELGIUM, A CORPORATION or BELGIUM cARRUREroR Application led July 7, 1927.l Serial No. 204,071.

This invention ,relates to carburetors for internal combustion engines, and embodies certain improvements upon the Structure shown, described and claimed in my pending application, Serial No. 162,803, filed J anuary 22, 1927. o In my prior application I havedisclosed a carburetor structure in which the supply of fuel into the mixing chamber is controlled by means of a suction operated, spring resistedvalve, whereby an initially over-rich mixture is temporarily supplied into the explosion chamber of the engine in starting up the motor from rest, and thereafter the fuel supply is controlled automatically by and proportionately to the suction action of the engme.

The present invention relates to carburetors of the same type, and its object is to simplify and improve the structure and operation of devices of this nature and to provide a structure which is economical to manufacture and the parts of which can be easily and readily assembled, and wherein the disastrous effects of back-fire are guarded against,

A further object is to provide means which are simple and eiicient for applying and detachably securing the carburetor structure vto the engine in connection with which it is to be used. o

Other objects of the invention will appear more fully hereinafter.

i The invention consists substantially in the construction, combination, location and relative arrangement of'parts, all as will be more fully hereinafter set forth, as shown in the accompanying drawing, and finally pointed out in the appended claims.

The single view of the drawing is a lon- 40 gitudinal central section of an illustrative form o f carburetor embodying the principles of my lnvention.

In the illustrative structure shown, the carburetor body is comprised of the two hollow cylindrical sections 3, 4, which are assembled and detachably secured together in endwise relation by any suitable means, such as the screws 5. Mounted within the section 4 is the Venturi tube 6, which may be held in place in any convenient manner, such, for exsupply tube 8, the respective ends of which, in

the form shown, extending beyond the wall of the section 4. One of the extending ends of tube 8 affords means for connecting Aa fuel supply pipe 11 thereto, and the other affords means to receive and adjust an fuel supply control needle Valve 13, the threaded end 13 of which is threaded into the bore of the tube .8. A screw head 17 permits the needle valve 13 to be adjusted. A screw cap 18, applied to and acting upon the tapered protruding end of tube 8, Serves to clamp and hold the needle Valve in its adjusted position.

The tube 8 not only lserves as a supply con duit for the fuel, but it also provides a support for the tubular nozzle body 9. To this end a sleeve member engages over the tube 8, and is provided with an interiorly threaded socket 10, .into which is screwed one end of the tubular nozzle body 9. This body 9 is formed with a chamber 12, which, when said body is screwed into supporting engagement with the socket 10, is brought into communication with the bore of tube 8, which is controlled by the needle valve 13. The interior chamber 12 is formed with an annular valve seat 16, with which coacts a valve 14, shown in this instance as a bell valve, which. is normally urged to its seat by means of a spring 15 The chamber 12 is prolonged beyond they Valve seat 16 to form an auxiliary space or chamber 19 in the bore of the nozzle body 9. Thisspace or chamber 19 is in communication with a mixing chamber 6', through an orifice or opening 20,- whi'ch I will call the slow running fuel jet opening. The mixing A chamber 6', communicates through an orifice 21 with an annular duct 22, which, in this instance, is shown as being formed inthe exterior surface of the Venturi tube 6. The l duct 22 communicates through a passage 23, 24, directlyinto the engine1 intake at a point beyond the usual throttle valve 25, as clearly shown.

The bore lof the nozzle body 9 is provided at a point beyond or outwardly of the auxiliary Space or chamber 19 with a cylindrical portion 19', and outwardly of this cylindrical portion of the bore are located the orifices 31, which open communication from the bore of the nozzle body 9 into the region of the narrowest portion of the mixing chamber 6 for delivery thereinto of the fuel. These orifices 31 constitute the main fuel outlets.

Mounted to slide longitudinally in the bore of the nozzle member 9 is a valve rod having a cylindrical end portion 29 which works through the tubular portion 19 of the nozzle bore'and extends into the auxiliary space or chamber 19, in position to engage and lift the valve 14'fr`om its seat when said valve rod is moved longitudinally into the nozzle bore. Adjacent the cylindrical portion 29 of the valve rod, said rod is formed with a slightly tapered portion 30, and outwardly from said slightly tapered portion .said rod is formed with a second portion 30 of greater -degree of taper. These two tapering portions 30, 30 serve to regulate the extent of opening permitted for the supply of fuel from the auxiliary space or chamber 19, through thei tubular portion 19 to the main i fuel outlet orifices 31. The stem portion 27 ments ofthe valve rod, I provide the outerl of the valve rod projects through the end closure cap 28 of the nozzle body 9, and has adjustably mounted thereon a disk member 26, which worksfreely in a 'short passage 3, formed in the outer end portion of the section 3 of the casing. The disk member 26 -controls the admission of outer .air into the sive charge to the engine.

In order to regulate and control the moveportion of the nozzle body 9 with a chamber 33', withinwhich operates a collar 33, which is mounted to slide on the stem 27, and is engaged by a spring 34, which keeps it normally pressed against an abutment 32 on the stem 27. A shoulder 35 vforming the end wall of the chamber 33', forms a'limit stop for the collar 33.

' As will be readily understood, the lsuction of the engine willcause the diskmember 26 to be drawn into the open end of the casing -member 3, to a greater or less extent according to the speed of the engine, thereby admitting a greater or less volume-of air to the mixing chamber. The slight initial suction action caused by Astarting the engine displaces the valve member 26 and draws air into the mixing chamber; This `movement vof the valve member 26 is communicated to the stem 27, and hence the end Aportion 29 of the valve rod is causedI to'engage and unseat valve 14, and the slightly tapered portion 30, of said rod opens the passage 19', thereby admitting fuel to the orifices 20 and 31, and thence into the mixing chamber and channels 22, 23, 24. 1 A

disk member 26,y or to independently actuatc,

the same,A I provide means for accomplishing that purpose, consisting, in this instance, of a iexible rod 36 arranged to be projected by button 37, or other suitable or convenient means, against the disk 26, when desired to effect the supply of fuel to the orifices 20, or 31, or both.

By opening the throttle 25, the suction action increases, thereby increasing the displacement of the disk member 26, and hence, also, of the valve rod actuated thereby. This increases the supply of fuel to the orifices 31. When the throttle 25 is closed, the re verse of this action takes place.

In case of back-fire, the expanding gases will act from inside the casing upon the disk member to move the same outwardly, thereby opening up instantly a wide exit path for said gases to the outer air and preventing damage or injury because of the explosion. The spring 34 will restore the valve rod and disk to their normal positions.

' In applying a carburetor to a motor engine it is frequently necessary'to rotatively adj ust the carburetor to accommodate the lead of the fuel supply pipe connection 39. It is also desirable to secure the carburetor to the engine by an efficient joint connection, which not only affords, but also which maintains, a tight and eiicient joint. In order to accomplish these results, I apply the end' surface of the body portion 4 of the casing directly and tightly againstthe planed ofl' surface of the boss on the engine which surrounds the intake opening. This application is effected by screwing an annular flange 38 onto the end of the casing 4, sufficiently to cause the end surface of the casing to extend beyond said flange, and then draw the entire carburetor body into its end surface seating against the planed surface of the boss by means of screw boltspassing through the flange, 4as clearly shown in the-drawing. This not only ensures and maintains atight joint, but it also permits .axial adjustment of the carburetor body ato accommodate any desired lead of the fuel supply pipe.

While I have shown and described only one practical embodiment of my invention, it is to beunderstood that my invention is capable of embodiment in various forms without departing from the scope or principles thereof. I do not desire, therefore, to be limited or restricted to the particular structure shown and described.

JBut what I claim as new and useful and of my own invention, andd desire to secure by Letters Patent is 1. In a carburetor construction a hollow body member having an air inlet and an air i outlet passage, a throttle valve in said outlet passage, a tube supported in said body `with an adjustable fuel control valve therein,

a tubular fuel supply body extending from said tube and in communication therewith, a ball valve in said tubular body having a seat, a valve stem slidable in said tubular body and cooperating with a seat therein to form a valve, a slow running fuel orifice controlled by the ball valve and normal running fuel orifices controlled by the valve on said stem,

all formed yin the tubular body and an air valve secured, to said stem and located in the air inlet passage and means to adjust the position of the air valve, the initial movement 0f theiair valve andstem opening the ball valve to admit fuel through the slow running fuel orifice and on further movement to ad- `mit fuel through the normal running fuel orifices.

2. In a carburetor construction a hollow body member having an air inlet and an air outlet passage, a throttle valve in said outlet passage, a tube supported in said body with an adjustable fuel control valve therein, a tubular fuel supply body extending from said tube and in communication therewith, a ball valve in said tubular body having a` seatfa valve stem slidable in said tubularbody and cooperating with a seat therein to form a valve, a slow running fuel orifice controlled by the ball valve and normal running fuel orifices controlled by the valve on said stem all formed in the tubular body and an air' valve secured to said stem and located in the air inlet passage, an air passage forming in the body member and opening on the outside of the throttle valve at one end and at the Vother adjacent the slow running fuel orifice and means to adjust the position of the air valve, the initial movement of the air valve and stein opening the ball valve to admit fuel through the slow running fuel orifice and on further movement to admit fuel through the normal running fuel orifices, the fuel flowing through the slowrunning fuel orifice after mixing with air flows through said airpas- 4 sage in the body member.

In testimony whereof I aii'ix my signature.

AL EMMANUEL MELKMAN. 

